efi/cper, cxl: Remove cper_cxl.h

efi/cper, cxl: Remove cper_cxl.h

Move the declaration of cxl_cper_print_prot_err() to include/linux/cper.h
to avoid maintaining a separate header file just for this function
declaration. Remove drivers/firmware/efi/cper_cxl.h as its contents have
been reorganized.

No functional changes.

Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://patch.msgid.link/20250123084421.127697-4-Smita.KoralahalliChannabasappa@amd.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>